Structural and conformational studies of derivatives of 2,4,8-trihydroxy-5-oxo-10-methylbenzo[1,2-c]chromene (alternariol). II: Crystal and molecular structure of (±)-1-methoxycarbonyl-1-hydroxy-2-oxa-3,4-dioxo-7-methoxy-9-methylcyclopenteno [3,4-c]chromene

The crystal and molecular structure of (±)-1-methoxycarbonyl-1-hydroxy-2-oxa-3,4-dioxo-7-methoxy-9-methylcyclopenteno3,4-c] chromene (Altox, II) has been determined by x-ray crystallographic methods. The crystals are monoclinic:a= 10.748,b = 9.644,c= 13.845 Å, = 104.58 °,Z = 4,P2₁/c. The structure was solved by direct methods and refined by full-matrix least-squares on 1158 symmetry-independent ¦F ₀¦-data toR = 6.9%. The molecules are linked by hydrogen bonds (O...O = 2.74 Å), forming a chain-like structure.